The study, published online in the Journal of Youth and Adolescence, was based on a nationally representative sample of 940 high school students across the country. The teens were surveyed by telephone in 2007 and 2008.

Overall, 27% of the students said their schools engaged in drug testing. However, the survey showed no evidence that drug-testing policies led male students to avoid drug use or engage in less drug use. Drug-testing policies seemed to have a slight impact on influencing female students not to use drugs, but the effect was found only in schools that have otherwise healthy social climates in which school rules are clear and enforced and student-adult relationships are based on respect.

Keep in mind, this isn’t a new revelation. The failures of random student drug testing have been known for years:

A 2003 study funded by the National Institute on Drug Abuse – the largest of its kind – examined 94,000 students at 900 schools in the U.S. and found no difference between levels of drug use at schools that test their students and those that do not. The same study found that drug testing programs are not widely accepted: 95 percent of American schools do not randomly drug test their student athletes, and only two percent of schools randomly test students who participate in extracurriculars other than athletics.

With costs ranging between $10 and $75 per test, it is unconscionable for federal dollars to be earmarked for a program of questionable effectiveness while schools struggle to adequately pay teachers and fund valuable extracurricular programs.

Many schools that drug test require students to produce urine samples while school officials stand outside the door listening for the sounds of urination to guard against tampered specimens. In addition to putting school officials at risk of being sued for sexual assault, this is invasive and embarrassing for students, and sends the message that they are guilty until proven innocent.

Prominent organizations that oppose random suspicionless student drug testing include the National Education Association, the Association for Addiction Professionals, the American Public Health Association, the American Academy of Pediatrics, the National Association of Social Workers, and the National Council on Alcoholism and Drug Dependence.

The lead author of the new study, Dan Romer, director of the Adolescent and Health Communications Institutes at the Annenberg Public Policy Center of the University of Pennsylvania, cautioned administrators to look at all evidence before adopting drug testing policies:

“This study sends a cautionary note to the estimated 20% or more of high schools that have joined the drug testing bandwagon,” Romer said in a news release. “We find little evidence that this approach to minimizing teen drug use is having the deterrent effect its proponents claim. . . Schools that have joined the rush to implement testing should ask themselves whether this strategy has been oversold.”